Upcoming talks on Iran's nuclear program will likely be held in Turkey, the EU's chief diplomat Javier Solana said Tuesday.

Solana said he expected to "achieve the most" at the Oct. 1 meeting because the United States will formally participate for the first time in the nuclear talks.

"I think that has to be evaluated positively by the Iranians," Solana told reporters.

Casting aside conditions that former President George W. Bush had set for talking with countries he called part of an "axis of evil," the Obama administration is making a play for progress after years of little movement.

Britain, France, Russia, China and Germany will also participate in the upcoming meeting.

"I think it will very likely be in Turkey," Solana said.

On Monday, Solana said the Oct. 1 meeting could set the stage for progress in resolving the standoff over the Islamic Republic's refusal to freeze uranium enrichment and heed other U.N. Security Council demands.

White House spokesman Robert Gibbs said enrichment — which can make both nuclear fuel and fissile warhead material — "would be part of the discussion," despite Iranian warnings it would not even discuss meeting U.N. Security Council demands that it freeze uranium enrichment.

The U.S., Israel and the EU fear that Iran is using its nuclear program to develop nuclear weapons. But Tehran says the program serves purely civilian purposes and that it has the right to enrich uranium for use in nuclear power plants.

The talks will be the first since a 2008 session in Geneva foundered over Iran's refusal to discuss enrichment.

In Washington, State Department spokesman Ian Kelly said Undersecretary of State for Political Affairs William Burns — who was at last year's Geneva talks as an observer — would again represent the U.S.

Washington's decision to talk with Iran appeared to be part of an attempt to preserve some six-power unity. Permanent Security Council members Russia and China have blocked Western attempts at tougher sanctions against Iran, so the agreement to drop insistence on an enrichment freeze and meet with Tehran without preconditions seemed gauged to keep Moscow and Beijing on board.

Sweden's Foreign Minister Carl Bildt, whose country holds the EU presidency said "it's much too early to discuss at the moment" a push for new sanctions.

"The focus now is on the meeting ... seeing if we can move forward on the agenda of trying to resolve the outstanding issues. I don't expect that to happen in one meeting."